One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,19)(12,21)(13,18)(14,15)(16,22)(17,23)(20,24)(25,26,31,33)(27,29,28,35)(30,32,38,40)(34,37,36,39)(1,2,5,6)(3,7,8,4)(10,15)(12,23)(16,19)(18,20)(25,26)(27,29)(28,35)(30,32)(31,33)(34,37)(36,39)(38,40)(2,6)(4,7)(10,15)(13,24)(16,19)(17,21)(25,27,31,28)(26,29,33,35)(30,36,38,34)(32,39,40,37)(2,6)(3,8)(9,11,14,22)(10,16,15,19)(12,18,23,20)(13,21,24,17)(25,28,31,27)(26,29,33,35)(30,36,38,34)(32,37,40,39)(1,3)(2,4)(5,8)(6,7)(9,12,14,23)(10,17,15,21)(11,20,22,18)(13,16,24,19)(25,29)(26,28)(27,33)(30,37)(31,35)(32,36)(34,40)(38,39)(1,4)(2,3)(5,7)(6,8)(9,13,14,24)(10,18,15,20)(11,21,22,17)(12,16,23,19)(25,30,31,38)(26,32,33,40)(27,34,28,36)(29,37,35,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.